Dental chair



F. E. CASE DENTAL CHAIR Sept. 23, 1924.

3 Sheets-Sheet 1 F. E. CASE DENTAL CHAIR Se t. 23, 1924. v

File A g- :50, 1922 :s Sheets-Sheet 2 Patented Sept. 23, 1924.

' 'UNITED STATES PATENT OFFICE.

FRANK E. CASE, OF CANTON, OHIQ, ASSIGNOR TO THE HARVARD COMPANY, 0 CAN- TON, OHIO, A CORPORATION OF OHIO.

DENTAL- CHAIR.

Application filed August 30, 1922.

To all 10. mm it may GOI'LGd/H-i lie it known that I, FRANK E. CASE, a citizen of the United States,'residing at Canton, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Dental Chairs, of which the following is a specification. v

The invention relates to dental. chairs and the like, in which the seat frame of the chair is transversely pivoted upon the pedestal for swinging forward and rearward thereon, and the object of the improvement is to provide clamping means for sustaining and securing the seat frame, in. the various positions into which it may be swung.

In dental chairs, the seat frame, the back support and the head rest, and the leg sup port and the foot rest, are usually connected or combined as a unitary structure, and the whole is mounted on transverse pivotal bearings located on the rear of the pedestal with the forward end of the seat frame normally resting on the front of the pedestal; and the combined weight of the superposed structure together with the weightof a. patient is so considerable, that difficulty is experienced in securing and holding the chair in a rcarwardly tilted position.

' To avoid this difficulty, the present invention involves the use of a plurality of steel strips depending from the forward portion of the seat frame, through and between a series of steel plates mounted in the front of the pedestal for sliding laterally therein, with adjustable and releasable means for clamping the strips and plates together to hold the chair in a given position of adjustment.

Dental chairs may also have the back support slidably fulcrumed to the seat support by means of an arcuate guide on the one and an arcuate slide on the other; and the weight of the back support and head rest together with the weightof a. reclining patient is so considerable, that difficulty is experienced in securing and holding the arcuate slide in a fixed position upon the arcuate guide.

To avoid this diiii'culty, the present invention involves the use of a clamping plate for sliding circumferentially upon the seat guide, a transverse wedge block adjust-able late ally in the back support, and an intervening roller impinging diverging of the plate and block with yielding "means nor- Serial No. 585,315.

Fig. 2, a fragmentary perspective view of a seat frame and pedestal, with a portion of the seat frame broken away to show details of the adjustable clamping means for the seat frame;

Fig. 3, a fragmentary section on line 33, Fig. 2, showing the adjustable clamping Means for the seat frame;

F 4:, a fragmentary section on line l4, Fig. 3, showing the arrangement of the depending clamping strips and the slidable clamping plates;

Fig. 5, a detached perspective view of one clamping plate;

Fig. 6, a detached perspective view of one clamping strip;

Fig. 7, a. detached perspective view of the clamping block; and

Fig. 8, a detached perspective view of the adjusting wedge.

Similar munerals refer to similar parts throughout the drawings.

The seat frame 15 is provided with transverse bearings 16 in the underside of its rear end which rest upon pivot trunnions 17 8X tending laterally each way from the rear side at the top of the pedestal 18, the bearings being retained on the trunnions by means of inverted caps 19 secured by screws 20; and a coiled spring 21 is preferably provided on the forward side of the top of the pedestal to cushion the bearing of the for-' ward end of the seat frame upon the pedestal.

A transverse pintle 22 is mounted in the forward end of the seat frame and may be mtegral wlth and extend from the side of a block 23 secured in an aperture 24 provided in the bottom 25 of the fran'ie, as by means of bolts26 passing through the bottom of the frame and engaging in flanges 27 and 27 extending forward and rearward from the lower side of the block.

A plurality of depending strips 28, preferably made of rolled steel, are pivoted by apertures 28 at their upper ends on the substantial distance beyond the strip 28 at the other side of the series; which protruding portion serves as a stop to abut a depending abutment lug 30 on the forward side of the pedestal 18, when the chair seat is a tilted rearward.

4 ward edges of the clamping plates 84, one

of which plates is located between each of the successive pairs of the clamping strips,

one at a time over the end of the pintle 22.

I as a retaining guide forthe and one or more of which may be provided with a' flange 34 on its inner edge to serve adjacent strip.

An outer portion 32 of the upper edge of the supporting wall 31 is recessed below the plate supporting portion 32 thereof, whiohvpermits the dove-tailed grooves of the clamping plates to be entered first over the lower edge vof the flange and then moved sideways, one at a time, along the supporting edge 32 as the strips 28 are assembled,

The outer end of the bearingwall 31 is connected to the forward side of the pedestal by a bearing wall 35; and after the strips and plates have been assembled, as shown in Figs. 2gand 3, a clamping block 36 l is inserted in the recess 37 between the bearing wall and the outer strip 28, the inner face 36 of which block bears against the side of the strip.

The clamping block is cut away in its forward side, to form a forwardly extending overhanging flange 88, and a forwardly 'extending lug 39 having its outerface 40 inclined downward and outward. A clamping screw 41 extends inward through the supporting wall 35, and between its end 41 and the inclined face of the lug 39, is located an adjusting wedge block 42 having its inner face 42 inclined to slide upon the outer face of the clamping lug 39, and having its outer face 42 substantially perpendicular to the axis of the clamping bolt 41.

A hook lug 43 extends forward from the top. of the wedge block and rests upon the recessed upper edge 32" of the supporting wall 31, as shown in Fig. 2, by means of which the block is supported; and a set screw 44 extends downward through the overhanging flange 38 at the top of the clamping block, and bears upon the top of the wedge block, and serves to support the clamping block upon the wedge block, as shown in F ig.3. A turning of the set screw serves to adjust the parts so that the clamping strips, plates, lugs and wedge block, will be in sliding contact between the depending lug 30 and the end of the clamping screw 41, whereupon a very slight turning of the screw will act to clamp all these parts together.

An operating lever 45 is secured to the outer end of a clamping screw 41 and. is provided with a pedal 46 on its rear end, which lever is normally held upward by an expansion spring 47 connecting the lever with the rear end of a bracket 48 secured to the pedestal; and a radial finger 41) on the pivoted end of the lever serves to stop a depression of the pedal by abutting the forward end 48 of the same bracket.

The parts are so arranged and adjusted and the strength of the expansion spring is such that the operating lever is normally held upward to clamp the strips 28 and plates 84 tightly together between the clamping block 36 and the abutment lug 30, which is the normal position of the parts; and that by a depression of the lever, as by the foot of an operator upon the pedal, the screw is rotated so that its clamping action is released, which permits the strips to slide upward and downward between the plates, as may be desired for an adjustment of the chair upon the pedestal.

The large area of the contiguous faces of the pendent strips with the faces of the abutment lug 30 and the clamping block 36 and with the faces of the intervening clumping plates 34, serves to retain and hold the seat rigidly in a given position of mljustnu-nt by the clamping action of the screw 41 and when this action is released by a slight turning of the screw, the strips are free to slide endwise between the contiguous surfaces. The necessary adjustment of the parts to act, as described, may be readily accomplished by a slight turning of the set screw 44 which acts upon the wedge block to change the relative position of the clamping block, as it is supported upon the wedge block.

I claim 1. A dental chair or the like including a pedestal, a tilting scat mounted thereon, an abutment in the pedestal, a plurality of strips depending from the seat, plates slidably supported by the pedestal between the several strips, an adjustable clamping block slidably supported by the pedestal, and means for clamping the plates and strips between the block and the abutment.

2. A dental chair or the like including a pedestal, a tilting seat mounted thereon, an abutment in the pedestal, a plurality of strips depending from the seat. plates slidably supported by the pedestal between the several strips. a wedge block slidahly supported by the pedestal, a clamping block adjustably supported by the wedge block, and means for clamping the plates and strips between the wedge and clamping blocks and the abutment.

3. A dental chair or the like including a pedestal, a tilting seat mounted thereon, an abutment in the pedestal, a plurality of strips depending from the seat, plates slidably supported by the pedestal between the several strips, an adjustable clamping block slidably supported by the pedestal, and a screw for clan'iping the plates and strips between the block and the abutment.

l. A dental chair or the like including a pedestal, a tilting seat mounted thereon, an abutment in the pedestal, a plurality of strips depending from the seat, plates slid-ably supported by the pedestal between the several strips, an adjustable clamping block slidably supported by the pedestal, a screw for clamping the plates and strips between the block and the abutment, and yielding means for turning the screw to clamp the plates and strips between the block and the abutment.

5. A dental chair or the like including a pedestal, a tilting seat mounted thereon, an abutment in the pedestal, a plurality of strips pivotally depending from the seat, plates slidably supported by the pedestal between the several strips, an adjustable clamping block slidably supported by the pedestal, and means for clamping the plates and strips between the block and the abutment.

6. A dental chair or the like including a pedestal, a tilting seat mounted thereon, an

abutment in the pedestal, a plurality of strips depending from the seat, plates slida-bly supported by the pedestal between the several strips, an adjustable clamping block slidably supported by the pedestal, means for clamping the plates and strips between the block and the abutment, anda pin aligning the lower ends of the strips.

7. A dental chair or the like including a pedestal, a tilting seat mounted thereon, an abutment in the pedestal, a plurality of strips depending from the seat, plates slidably supported by the pedestal between the several strips, an adjustable clamping block slidably supported by the pedestal, means for clamping the plates and strips between the block and the abutment, and a stop pin at the lower end of the strips to impinge the lower end of the abutment lug.

FRANK E; CASE. 

